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变形量对热压/热变形纳米复合Nd_9Fe_(84.5)Co_1B_(5.5)永磁体晶粒尺寸和矫顽力的影响 被引量:2
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作者 刘艳君 潘晶 +2 位作者 张文旺 林金荣 刘新才 《功能材料》 EI CAS CSCD 北大核心 2011年第9期1727-1730,共4页
采用热压/热变形工艺制备纳米复合Nd9Fe84.5Co1B5.5永磁体,研究了热变形过程中的变形量对磁体平均晶粒尺寸的影响以及由此带来的晶间相互作用和矫顽力的变化。结果表明变形量54%的磁体中的硬、软磁性相的平均晶粒尺寸分别为61.0和51.8nm... 采用热压/热变形工艺制备纳米复合Nd9Fe84.5Co1B5.5永磁体,研究了热变形过程中的变形量对磁体平均晶粒尺寸的影响以及由此带来的晶间相互作用和矫顽力的变化。结果表明变形量54%的磁体中的硬、软磁性相的平均晶粒尺寸分别为61.0和51.8nm,与其热压状态时的两相平均晶粒尺寸(52.1和54.0nm)接近;而变形量74%的磁体中的硬、软磁性相的平均晶粒尺寸则分别显著减小至19.2和22.4nm。随着两相晶粒尺寸的显著细化,磁体中的晶间相互作用由以静磁耦合作用为主转变为以晶间交换耦合作用为主,这导致其矫顽力提高了64%。 展开更多
关键词 热压/热变形纳米复合磁体 变形量 粒尺寸 晶间相互作用 矫顽力
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Regulating crystal phase of TiO_(2) to enhance catalytic activity of Ni/TiO_(2) for solar-driven dry reforming of methane
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作者 HE Zhanjun GONG Kun +3 位作者 DAI Yuanyuan NIU Qiang LIN Tiejun ZHONG Liangshu 《燃料化学学报(中英文)》 EI CAS CSCD 北大核心 2024年第9期1203-1213,共11页
Ni/TiO_(2) catalyst is widely employed for photo-driven DRM reaction while the influence of crystal structure of TiO_(2) remains unclear.In this work,the rutile/anatase ratio in supports was successfully controlled by... Ni/TiO_(2) catalyst is widely employed for photo-driven DRM reaction while the influence of crystal structure of TiO_(2) remains unclear.In this work,the rutile/anatase ratio in supports was successfully controlled by varying the calcination temperature of anatase-TiO_(2).Structural characterizations revealed that a distinct TiO_(x) coating on the Ni nanoparticles(NPs)was evident for Ni/TiO_(2)-700 catalyst due to strong metal-support interaction.It is observed that the TiOx overlayer gradually disappeared as the ratio of rutile/anatase increased,thereby enhancing the exposure of Ni active sites.The exposed Ni sites enhanced visible light absorption and boosted the dissociation capability of CH4,which led to the much elevated catalytic activity for Ni/TiO_(2)-950 in which rutile dominated.Therefore,the catalytic activity of solar-driven DRM reaction was significantly influenced by the rutile/anatase ratio.Ni/TiO_(2)-950,characterized by a predominant rutile phase,exhibited the highest DRM reactivity,with remarkable H_(2) and CO production rates reaching as high as 87.4 and 220.2 mmol/(g·h),respectively.These rates were approximately 257 and 130 times higher,respectively,compared to those obtained on Ni/TiO_(2)-700 with anatase.This study suggests that the optimization of crystal structure of TiO_(2) support can effectively enhance the performance of photothermal DRM reaction. 展开更多
关键词 dry reforming of methane photothermal catalysis crystal phase TiO_(2) metal-support interaction
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Real-Time Characterization of Fibrinogen Interaction with Modified Titanium Dioxide Film by Quartz Crystal Microbalance with Dissipation
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作者 An-sha Zhao Zhao Wang +2 位作者 Xiao-hua Zhu Manfred F. Maitz Nan Huang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第3期355-360,共6页
The adsorption of fibrinogen can be used as a quick indicator of surface haemocompatibility because of its prominent role in coagulation and platelet adhesion. In this work the molecular interaction between fibrinogen... The adsorption of fibrinogen can be used as a quick indicator of surface haemocompatibility because of its prominent role in coagulation and platelet adhesion. In this work the molecular interaction between fibrinogen and a modified titanium oxide surface/platelet has been studied by quartz crystal microbalanee with dissipation (QCM-D) in situ. In order to further characterize the conformation of adsorbed fibrinogen, αC and γ-chain antibody were used to check the orientation and denaturation of fibrinogen on solid surface. QCM-D investiga- tions revealed the fibrinogen have the trend to adsorb on hydropllilic surface in a side-on orientation by positively charged αC domains, which would reduce the exposure of platelet bonding site on γ chain and enable less platelet adhesion and be activated. These obser- vations suggest that certain conformations of adsorbed fibrinogen are less platelet adhesive than others, which opens a possibility for creating a non-platelet adhesive substrates. 展开更多
关键词 Quartz crystal microbalance with dissipation Fibrinogen adsorption Confor- mation change Blood platelet
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Nd_9Fe_(85.5-x)Co_xB_(5.5)(x=0,1,3,5)合金快淬薄带及其热变形磁体的微观组织与矫顽力 被引量:2
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作者 张文旺 潘晶 +3 位作者 刘新才 郭鹏举 刘艳君 李柱柏 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2011年第4期600-604,共5页
以Nd9Fe85.5-xCoxB5.5(x=0,1,3,5)合金快淬薄带(钼辊表面速度V=35m/s)为原料采用热压/热变形工艺制备了各向同性磁体。微观组织研究表明,含Co合金快淬薄带由大量非晶和少量α-(Fe,Co)和Nd2(Fe,Co)14B相组成,含Co量达到5at%的合金薄带中... 以Nd9Fe85.5-xCoxB5.5(x=0,1,3,5)合金快淬薄带(钼辊表面速度V=35m/s)为原料采用热压/热变形工艺制备了各向同性磁体。微观组织研究表明,含Co合金快淬薄带由大量非晶和少量α-(Fe,Co)和Nd2(Fe,Co)14B相组成,含Co量达到5at%的合金薄带中出现了亚稳相Nd3(Fe,Co)62B14,它在随后的热压/热变形过程中分解为α-(Fe,Co)和Nd2(Fe,Co)14B;添加Co元素显著减小了热变形磁体的晶粒尺寸,软磁性相与硬磁性相的平均晶粒尺寸分别从无Co合金磁体的61,168nm减小为含1at%Co合金磁体的24,50nm。磁性能研究表明,与晶粒尺寸变化相对应,无Co合金以晶间静磁耦合作用为主,含Co合金以晶间交换耦合作用为主,并且随着Co含量的升高,交换耦合作用有所减弱,导致热变形磁体的矫顽力从无Co磁体的151kA/m单调增大为含5at%Co磁体的218kA/m。 展开更多
关键词 ND2FE14B/Α-FE 热变形磁体 添加Co 晶间相互作用 矫顽力
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Pressure-induced changes in the magnetic properties of the single crystal of Mn_3 single-molecule magnet 被引量:1
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作者 CUI Yan WU Yue +3 位作者 LI YanRong LIU RuiYuan DONG XiaoLi WANG YunPing 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第7期1299-1303,共5页
The magnetic measurements of the single crystal of Mn3 single-molecule magnet under high pressure at T=2 K have been performed.We find both the antiferromagnetic intermolecular coupling parameter J and the effective e... The magnetic measurements of the single crystal of Mn3 single-molecule magnet under high pressure at T=2 K have been performed.We find both the antiferromagnetic intermolecular coupling parameter J and the effective energy barrier to vary compared with the measurements at low pressure.The increase of|J|is estimated to be 12%at 0.7 GPa when compared with that of0 GPa,whereas the effective energy barrier becomes smaller with increasing pressure.Our results demonstrate that the intermolecular interaction of single-molecule magnet can be changed by pressure.Compared with the normal magnetic alloy,the effect of pressure on the magnetic properties of Mn3 is much more prominent,which implies that Mn3 may have great potential in magnetic multifunctional material. 展开更多
关键词 single-molecule magnet exchange coupling quantum tunneling of magnetization quasi-hydrostatic pressure
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